The object of the present invention is an agent for coloring keratin fibers, for example silk, wool or hair and particularly human hair, said agent containing (i) a heterocyclic hydrazone derivative, (ii) an aromatic enamine and (iii) an oxidant, a multicomponent kit and a method for coloring keratin fibers by use of said coloring agent.
Hair colorants are divided mainly into the groups of oxidation colorants and tinting agents, depending on the initial color of the hair to be dyed and on the desired end result. Oxidation colorants are eminently suited for covering large gray areas, the oxidation colorants used for gray areas of up to 50% as a rule being referred to as oxidative tinting agents, and the oxidation colorants used for gray areas of more than 50% or for “brightening” usually being referred to as oxidative colorants. Direct dyes are contained primarily in non-oxidative colorants (tinting agents). Because of their small molecular size, some direct dyes, for example the nitro dyes, can penetrate into the hair and dye it directly, at least in the outer regions. Such coloring is very gentle to the hair and as a rule can withstand 6 to 8 hair washings. Direct dyes are also frequently used in oxidative colorants for producing certain shades or to intensify the color.
DE-A 1 922 400 discloses the use of hydrazones for coloring keratin fibers. These colorants, however, cannot meet the requirements placed on colorants in every respect, particularly in terms of the luster and intensity of the colorations.